I am sooooo sad too! I ordered these as a pre-order back in early May and have been on pins and needles waiting for them to arrive in the mail. As soon as I took them out of the bag this morning my smile was turned up side down!

He is pretty big for his age (about the size of a two year old) Currently in between 18-24 months in clothing. Really solid/cubby thighs. He could probably wear the wool shorts for a month or so but I should have sized up. I think these would work great on a 9-12-18month old.

These are great. Have you tried them on? They are super stretchy. My DD who is (almost) 2 years old, 28 pounds, 33" and wearing a 2T mostly can wear mediums. She has a pair of larges that she wears at night over a giant night time fitted and they barely stay up. MLs would be better for her for longies, but she wears M shorties perfectly.
If I didn't have enough M shorties, I probably wouldn't be suggesting you try them on.